1. Technical Field
The present invention relates to signal processing, and more particularly to an encoding method and system for quasi low-density parity-check (LDPC) code.
2. Description of the Related Art
Low-Density-Parity-Check (LDPC) codes are commonly given in the form of a parity check matrix H. The generator matrix G is required to be orthogonal with parity the check matrix H, such that H·GT=[O], where [O] is zero matrix. Generator matrix G is preferred to be in (or close to) systematic form, i.e., the form of [I|G′] where I is an identity matrix, so that the encoded data will be composed of direct information bits and parity check bits. Most of the existing encoding methods do not provide systematic form. Such methods increase encoding complexity, and also lead to the difficulty in direct extraction of information bits without decoding.